DSpace Collection:http://hdl.handle.net/2122/146
Sat, 10 Dec 2016 02:58:15 GMT2016-12-10T02:58:15ZCombining model and geostationary satellite data to reconstruct hourly SST field over the Mediterranean Seahttp://hdl.handle.net/2122/10019
Title: Combining model and geostationary satellite data to reconstruct hourly SST field over the Mediterranean Sea
Authors: Marullo, S.; Agenzianazionaleperlenuovetecnologie,l'energiaelosviluppoeconomicosostenibile,ENEA—CentroRicercheFrascati,Frascati,Italy; Santoleri, R.; CNR—IstitutodiScienzedel'AtmosferaedelClima,Rome,Italy; Ciani, D.; CNR—IstitutodiScienzedel'AtmosferaedelClima,Rome,Italy; Le Borgne, P.; Meteo-France/DP/CMS, Lannion, France; Pere, S.; Meteo-France/DP/CMS, Lannion, France; Pinardi, N.; DepartmentofPhysicsandAstronomy,UniversityofBologna,Italy; Tonani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Nardone, G.; IstitutoSuperioreperlaProtezioneelaRicercaAmbientale(ISPRA),Italy
Abstract: This work focuses on the reconstruction of Sea Surface Temperature (SST) diurnal cycle through combination of numerical model analyses and geostationary satellite measurements. The approach takes advantage of geosta- tionary satellite observations as the diurnal signal source to produce gap-free optimally interpolated (OI) hourly SST fields using model analyses as first-guess. The resulting SST anomaly field (satellite-model) is free, or nearly free, of any diurnal cycle, thus allowing one to interpolate SST anomalies using satellite data acquired at different times of the day.
The method is applied to reconstruct the hourly Mediterranean SST field during summer 2011 using SEVIRI data and Mediterranean Forecasting System analyses. A synthetic cloud reconstruction experiment demonstrated that the OI SST method is able to reconstruct an unbiased SST field with a RMS = 0.16 °C with respect to SEVIRI observations. The OI interpolation estimate, the model first guess and the SEVIRI data are evaluated using drifter and mooring measurements. Special attention is devoted to the analysis of diurnal warming (DW) events that are particularly frequent in the Mediterranean Sea. The model reproduces quite well the Mediterranean SST diurnal cycle, except for the DW events. Due to the thickness of the model surface layer, the amplitude of the model diurnal cycle is often less intense than the corresponding SEVIRI and drifter observations. The Diurnal OI SST (DOISST) field, resulting from the blending of model and SEVIRI data via optimal interpolation, reproduces well the diurnal cycle including extreme DW events. The evaluation of DOISST products against drifter measure- ments results in a mean bias of −0.07 °C and a RMS of 0.56 °C over interpolated pixels. These values are very close to the corresponding statistical parameters estimated from SEVIRI data (bias = −0.16 °C, RMS = 0.47 °C). Results also confirm that part of the mean bias between temperature measured by moorings at 1 m depth and the satellite observations can be ascribed to the different nature of the measurements (bulk versus skin).Tue, 31 Dec 2013 23:00:00 GMThttp://hdl.handle.net/2122/100192013-12-31T23:00:00ZANNALS OF GEOPHYSICS: AD MAJORAhttp://hdl.handle.net/2122/9916
Title: ANNALS OF GEOPHYSICS: AD MAJORA
Authors: Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Bianco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; De Michelis, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Caprara, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Chiodetti, A. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Gresta, S.; Univ Catania
Abstract: Annals of Geophysics (ISSN: 1593-5213; from 2010, 2037-416X) is a bimonthly international journal, which publishes scientific papers in the field of geophysics sensu lato. It derives from Annali di Geofisica (ISSN: 0365-2556), which commenced publication in January 1948 as a quarterly periodical devoted to general geophysics, seismology, Earth magnetism, and atmospheric studies....Tue, 31 Dec 2013 23:00:00 GMThttp://hdl.handle.net/2122/99162013-12-31T23:00:00ZOcean, sea-ice, atmosphere oscillations in the Southern Ocean as simulated by the SINTEX coupled modelhttp://hdl.handle.net/2122/8948
Title: Ocean, sea-ice, atmosphere oscillations in the Southern Ocean as simulated by the SINTEX coupled model
Authors: Carril, A. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Navarra, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia
Abstract: 1This study evaluates the Antarctic Circumpolar Wave
(ACW) as simulated by the SINTEX coupled model. We
found evidence that sea-ice treatment plays a crucial role
on simulating the ACW. In particular, SST anomalies at
interannual time scales describe a propagating ACW-like
pattern when a dynamic thermodynamic sea-ice model
is coupled with the ocean, but when sea-ice is relaxed
to climatology, anomalies occur as zonally symmetric
patterns that do not propagate in longitude. Moreover,
from the experiment with an active sea-ice component
we saw that ACW-like oscillations are strongly modulated
by low frequency variability. Our result adds some
extra confidence to previous studies based on relatively
short series of observed data.Fri, 28 May 2004 22:00:00 GMThttp://hdl.handle.net/2122/89482004-05-28T22:00:00ZMonitoraggio sismico del territorio nazionale: stato dell'arte e sviluppo delle reti di monitoraggio sismicohttp://hdl.handle.net/2122/8813
Title: Monitoraggio sismico del territorio nazionale: stato dell'arte e sviluppo delle reti di monitoraggio sismico
Authors: Sergio, Guardato; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia
Abstract: Il sistema CUMAS (Cabled Underwater Module
for Acquisition of Seismological data) è un
prodotto tecnologico-scientifico complesso nato
con il Progetto V4 [Iannaccone et al., 2008] allo
scopo di monitorare l’area vulcanica dei Campi
Flegrei (fenomeno del bradisismo).
Si tratta di un modulo sottomarino cablato e
connesso a una boa galleggiante (meda elastica). Il
sistema è in grado di acquisire e trasmettere alla
sala di monitoraggio dell’OV, in continuo e in
tempo reale, sia i segnali sismologici sia quelli di
interesse geofisico ed oceanografico (maree,
correnti marine, segnali acustici subacquei,
parametri funzionali di varia natura).
Il sistema è in grado di ricevere comandi da remoto
per variare diversi parametri di acquisizione e di
monitorare un cospicuo numero di variabili di
funzionamento.
Il sistema si avvale del supporto di una boa
galleggiante attrezzata. La boa è installata a largo
del golfo di Pozzuoli (Napoli) a circa 3 km dalla
costa. Il modulo sottomarino, collegato via cavo
alla parte fuori acqua della boa, è installato sul
fondale marino a una profondità di circa 100 metri.Fri, 31 Dec 2010 23:00:00 GMThttp://hdl.handle.net/2122/88132010-12-31T23:00:00ZModelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarcticahttp://hdl.handle.net/2122/5744
Title: Modelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarctica
Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Coluccelli, A.; UniPoliMa; Ravaioli, F.; CNR-ISMAR; Giglio, F.; CNR-ISMAR; Langone, L.; CNR-ISMAR; Azzaro, M.; CNR-IAMC; Azzaro, F.; CNR-IAMC; La Ferla, R.; CNR-IAMC; Catalano, G.; CNR-ISMAR; Cozzi, S.; CNR-ISMAR
Abstract: Several biogeochemical data have been collected in the last 10 years of Italian activity in Antarctica (ABIOCLEAR, ROSSMIZE, BIOSESO-I/II). A comprehensive 1-D biogeochemical model was implemented as a tool to link observations with processes and to investigate the mechanisms that regulate the flux of biogenic material through the water column. The model is ideally located at station B (175° E–74° S) and was set up to reproduce the seasonal cycle of phytoplankton and organic matter fluxes as forced by the dominant water column physics over the period 1990–2001. Austral spring-summer bloom conditions are assessed by comparing simulated nutrient drawdown, primary production rates, bacterial respiration and biomass with the available observations. The simulated biogenic fluxes of carbon, nitrogen and silica have been compared with the fluxes derived from sediment traps data. The model reproduces the observed magnitude of the biogenic fluxes, especially those found in the bottom sediment trap, but the peaks are markedly delayed in time. Sensitivity experiments have shown that the characterization of detritus, the choice of the sinking velocity and the degradation rates are crucial for the timing and magnitude of the vertical fluxes. An increase of velocity leads to a shift towards observation but also to an overestimation of the deposition flux which can be counteracted by higher bacterial remineralization rates. Model results suggest that the timing of the observed fluxes depends first and foremost on the timing of surface production and on a combination of size-distribution and quality of the autochtonous biogenic material. It is hypothesized that the bottom sediment trap collects material originated from the rapid sinking of freshly-produced particles and also from the previous year's production period.Wed, 31 Dec 2008 23:00:00 GMThttp://hdl.handle.net/2122/57442008-12-31T23:00:00ZAn enhanced sea-ice thermodynamic model applied to the Baltic seahttp://hdl.handle.net/2122/5743
Title: An enhanced sea-ice thermodynamic model applied to the Baltic sea
Authors: Tedesco, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Haapala, J.; Finnish Institute of Marine Research; Stipa, T.; Finnish Institute of Marine Research
Abstract: A refined Semtner 0-layer sea-ice model (ESIM1) is presented and applied to the Baltic landfast sea-ice. The physical model is capable of simulating seasonal changes of snow and ice thickness. Particular attention is paid to reproducing the snow-ice and the super-imposed-ice formation which play important roles in the total mass balance of the Baltic sea-ice. The model prognostic variables include all kinds of ice and snow layers that may be present during a Baltic landfast ice season and, in general, in every coastal area of an ice-covered ocean. The assessment of the model capabilities was done for 1979–1993 for four different stations in the Baltic Sea. A sensitivity test stresses the relevant role of some of the physical parameters, such as the oceanic heat flux, while a scenario analysis highlights the robustness of the model to perturbed physical forcing. Our results show that one of the key variables in modelling sea-ice thermodynamics is the snow layer and its metamorphism, and including the meteoric ice dynamics into a sea ice model is relevant to properly simulate any ice season, also in view of climate change scenariosThu, 26 Feb 2009 23:00:00 GMThttp://hdl.handle.net/2122/57432009-02-26T23:00:00ZAn enhanced sea-ice thermodynamic model applied to the Baltic Seahttp://hdl.handle.net/2122/4529
Title: An enhanced sea-ice thermodynamic model applied to the Baltic Sea
Authors: Tedesco, L.; Centro Euro Mediterraneo per i Cambiamenti Climatici; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Haapala, J.; Finnish Institute of Marine Research; Stipa, T.; Finnish Institute of Marine Research
Abstract: A refined Semtner 0-layer sea-ice model (ESIM1) is presented and applied to the Baltic landfast sea-ice. The physical model is capable of simulating seasonal changes of snow and ice thickness. Particular attention is paid to reproducing the snow-ice and the super-imposed-ice formation which play important roles in the total mass balance of the Baltic sea-ice. The model prognostic variables include all kinds of ice and snow layers that may be present during a Baltic landfast ice season and, in general, in every coastal area of an ice-covered ocean. The assessment of the model capabilities was done for 1979–1993 for four different stations in the Baltic Sea. A sensitivity test stresses the relevant role of some of the physical parameters, such as the oceanic heat flux, while a scenario analysis highlights the robustness of the model to perturbed physical forcing. Our results show that one of the key variables in modelling sea-ice thermodynamics is the snow layer and its metamorphism, and including the meteoric ice dynamics into a sea ice model is relevant to properly simulate any ice season, also in view of climate change scenariosMon, 31 Dec 2007 23:00:00 GMThttp://hdl.handle.net/2122/45292007-12-31T23:00:00ZHistorical behaviour of Dome C and Talos Dome (East Antarctica) as investigated by snow accumulation and ice velocity measurementshttp://hdl.handle.net/2122/3751
Title: Historical behaviour of Dome C and Talos Dome (East Antarctica) as investigated by snow accumulation and ice velocity measurements
Authors: Urbini, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Frezzotti, M.; enea casaccia; Gandolfi, S.; università di bologna; Vincent, C.; LGGE Grenoble; Scarchilli, C.; enea casaccia; Vittuari, V.; università di bologna; Fily, M.; LGGE Grenoble
Abstract: Ice divide–dome behaviour is used for ice sheet mass balance studies and interpretation of ice core records. In order to characterize the historical behaviour (last 400 yr) of Dome C and Talos Dome (East Antarctica), ice velocities have been measured since 1996 using a GPS system, and the palaeo-spatial variability of snow accumulation has been surveyed using snow radar and firn cores. The snow accumulation distribution of both domes indicates distributions of accumulation that are non-symmetrical in relation to dome morphology. Changes in spatial distributions have been observed over the last few centuries, with a decrease in snow accumulation gradient along the wind direction at Talos Dome and a counter-clockwise rotation of accumulation distribution in the northern part of Dome C. Observations at Dome C reveal a significant increase in accumulation since the 1950s, which could correlate to altered snow accumulation patterns due to changes in snowfall trajectory. Snow accumulation mechanisms are different at the two domes: a wind-driven snow accumulation process operates at Talos Dome, whereas snowfall trajectory direction is the main factor at Dome C. Repeated GPS measurements made at Talos Dome have highlighted changes in ice velocity, with a deceleration in the NE portion, acceleration in the SW portion and migration of dome summit, which are apparently correlated with changes in accumulation distribution. The observed behaviour in accumulation and velocity indicates that even the most remote areas of East Antarctica have changed from a decadal to secular scale.Thu, 31 Jan 2008 23:00:00 GMThttp://hdl.handle.net/2122/37512008-01-31T23:00:00ZModelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarcticahttp://hdl.handle.net/2122/3453
Title: Modelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarctica
Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Coluccelli, A.; UNIVPM, Italy; Ravaioli, M.; CNR-ISMAR; Giglio, F.; CNR-ISMAR; Langone, L.; CNR-ISMAR; Azzaro, M.; CNR-IAMC; Azzaro, F.; CNR-IAMC; La Ferla, R.; CNR-IAMC; Cozzi, S.; CNR-ISMAR; Catalano, G.; CNR-ISMAR
Abstract: Abstract Several biogeochemical data have been collected in the last 10 years of Italian activity in Antarctica (ABIOCLEAR, ROSSMIZE, BIOSESO-I/II). A comprehensive 1-D biogeochemical model was implemented as a tool to link observations with processes and to investigate the mechanisms that regulate the flux of biogenic material through the water column. The model is ideally located at station B (175^{o}E - 74^{o}S) and was set up to reproduce the seasonal cycle of phytoplankton and organic matter fluxes as forced by the dominant water column physics over the period 1990-2001. Austral spring-summer bloom conditions are assessed by comparing simulated nutrient drawdown, primary production rates, bacterial respiration and biomass with the available observations. The simulated biogenic fluxes of carbon, nitrogen and silica have been compared with the fluxes derived from sediment traps data. The model reproduces quite well the magnitude of the biogenic fluxes, expecially those observed in the bottom sediment trap, but the peaks are delayed in time. Sensitivity experiments have shown that the characterization of detritus, the choice of the sinking velocity and the degradation rates are crucial for the timing and magnitude of the vertical fluxes. An increase of velocity leads to a shift towards observation but also to an overestimation of the deposition flux which can be counteracted by higher bacterial remineralization rates. Model results suggest that observed fluxes could be explained by the size-distribution and quality of the locally-produced biogenic material. It is hypothesized that the bottom sediment trap collects material originated from rapid sinking of particles and also from previous years production periods, likely modulated by advective and aggregation mechanisms which are still not resolved by the model.Sun, 31 Dec 2006 23:00:00 GMThttp://hdl.handle.net/2122/34532006-12-31T23:00:00ZDevelopment of a numerical model of sea ice for biogeochemical studies. Part 1: Sea-ice thermodynamicshttp://hdl.handle.net/2122/3435
Title: Development of a numerical model of sea ice for biogeochemical studies. Part 1: Sea-ice thermodynamics
Authors: Tedesco, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Haapala, J.; Finnish Institute of Marine Research, Helsinki, Finland; Stipa, T.; Finnish Institute of Marine Research, Helsinki, Finland
Abstract: A fully prognostic 1-D thermodynamic model, functional for studies of sea-ice
biogeochemistry is developed to better understand the physical processes and the
interactions between the environment and the sea-ice ecosystem. The physical model
is capable of simulating seasonal changes of snow and ice thickness. Particular
attention is paid to reproduce the snow-ice and the superimposed ice formation
which play important roles in the dynamics of sea ice algae. The assessment of the
model capabilities is done in 1979--1993 at four different stations in the Baltic Sea.
A sensitivity analysis stresses the importance of adequate surface forcing functions to
properly simulate the onset of sea ice. Our results show that thickness of the ice
layers and timing of the melting are in good agreement with the observed data and
confirm that one of the key variables in modelling sea-ice thermodynamics is the
snow layer and its metamorphism.Sun, 31 Dec 2006 23:00:00 GMThttp://hdl.handle.net/2122/34352006-12-31T23:00:00Z